I think that the content here doesn't go very deep into
details on any specific subject it covers, but it succeeds
in introducing the pieces that a computer network consists
from. I would propose this book to be basic education for
anybody.

Some of the educational value in the book has been replaced
by historical by now though. The publishing online was a new
thing when it came out. Today, publishing content on a
website is not nearly as often done as it should be, but
it's not a new thing anymore.

Many of the links in the book have rot away. The content
they used to refer to is no longer online. Hosts in their
respective domains are no longer there and the servers
serving these links are no longer out there waiting for you
to say 'hello' to them.

Basics mentioned in appear to still hold, but some
of the content is outdated. The hardware has went forward.
For example you no longer find hubs and bridges anywhere
because they've been replaced by ethernet switches. On the
other hand the protocols seem to still be relevant. Even
those that sound obscure to me such as the RTP and RSVP seem
to have some modern relevance.

Update: I was told that even the discussion about hubs and
bridges still may matter because their behavior still exists
in practice.

The "Top down" approach of the book is quite tiresome to
start with and if you don't take it in multiple reading
sessions you'll be really tired when you get to the later
chapters that are more interesting. Despite this the
approach still seems to make sense somewhat because below
the link layer it's not clear what "the bottom" should be
and what will it be in the future?

A naive person may associate networking to ethernet cables for
instance. After all when you unplug that cable out of a
computer you lose access to Internet. But this is not a
valid bottom because you can also run a link through a HDMI
or USB cable. Although a very lot hasn't changed in
certain perspective, there has still been the potential of
change. Makes no stable bottom for "Bottom up" approach of
writing a textbook.